Electric bill too high?

I am all electric with storage heating and I pay �70 per month throughout the year, obviously don't use the heating in the summer months but still have to pay the same amount to balance out the more expensive winter months but that is �840 per year so how can your possibly be �10,000 for a few years, it would take be 11 years to use that amount? What they are doing by adding any arrears onto your bill is correct but surely they do not expect you to pay �10 per day in electric? I would contact them and find out if the amount they are charging is the correct amount and ask them why they are doing this if you paid your bill? Good Luck